how to empty guest's shopping cart after the browser close?

[quardas]

How to clean up the guest's shopping cart after the browser close (after closing all tabs of the browser). I want to always have empty shopping cart when I'm visiting the store web-page by first time. Do you have any ideas or working solutions?

[shacker]

better make a cron job to execute a sql query to delete guests carts once a day. 

 

for example: 

SELECT * FROM `'._DB_PREFIX_.'cart` WHERE `id_customer` = 0

 

but you need to use a delete sentence